uniform sampler2D RTScene; // the texture with the scene you want to blur
uniform float resolution;
uniform int mySize;

varying vec2 vTexCoord;

void main(void)
{
	vec4 sum = vec4(0.0);
	
	for (int i = 0; i < (2 * mySize+1); i++)
	{ 
		sum += texture2D(RTScene, vec2(vTexCoord.x - (i-mySize ) / resolution, vTexCoord.y))/((mySize*2)+1);
    }
 
	gl_FragColor = sum;
}